Pen



FIG. 1 is a front, right side top perspective view of a pen showing mynew design;

FIG. 2 is a front, right side top exploded view of the pen shown in FIG.1;

FIG. 3 is a right side elevational view of the pen shown in FIG. 1; theleft side being identical thereto;

FIG. 4 is a right side elevational view of the pen slightly rotated inrelation to FIG. 3;

FIG. 5 is a top plan view of the pen shown in FIG. 1; and,

FIG. 6 is a bottom plan view of the pen shown in FIG. 1.

The structure in broken lines forms no part of the claimed design.

The ornamental design for a pen, as shown and described.